| 摘要 |
PROBLEM TO BE SOLVED: To provide a copyright protection method capable of protecting a right of an author. SOLUTION: In a transmission side of digital information, the digital information is ciphered by a first ciphering key, and the first ciphering key is ciphered by a second ciphering key. Then, the ciphered digital information is added with the ciphered first ciphering key to be transmitted. Then, in the receiving side of the digital information, the ciphered first ciphering key is deciphered by the second ciphering key, and the ciphered digital information is deciphered by the first ciphering key obtained by the result of the deciphering. |
